Canine IgA and IgA deficiency

Immunoglobulin A (IgA) is an important antibody involved in protective responses on mucosal surfaces,  such as the intestines. Low IgA has been associated with canine atopic dermatitis (CAD), as well as recurrent respiratory and gastrointestinal infections. Higher IgA has been associated with increased inflammation.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6855239/